Electropneumatic brake



July 9, 1929. T* H, THOMAS 1,720,250

ELEGTROPNEUMATIG BRAKE Filed Aug, 4, 1927 @mmm lllllll ATTORNEY Patented July 9, 1929. i

UNITED STATES i 1,720,250 PATENT OFFICE.

THOMAS H. THOMAS, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR '10 THE WESTING- HOUSE AIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

Application filed August 4, 1927.

This invention relates to electro-pneumatic brake equipments, and more particularly to an electro-pneumatie brake equipment employing a single train wire and having a ground return.

The principal object of my invention is to provide Y an improved electro-pneumatic brake equipment of the above type.

In the accompanying drawing, the single figure is a diagrammatic view of an electropneumatic brake equipment embodying my invention.

According to my invention, two sources of electric current are employed, a direct current source, such as the battery 1, and a source of alternating current, such as the alternating current generator 2.

In the circuit ot the generator 2 is a primary coil 3 co-operating with a secondary coil 4 disposed in circuit with tlv single tra-in wire 5. A brake switch is provided which may be associated with the usual brake valve device, so that on the locomotive, the brakes are applied and released by operation of the brake valve device, while on the cars, the brakes are controlled electrically by the operation of the brake switch, which is moved with the brake valve device.

On each car of the train, magnets 6 and 7 are provided, each having onev terminal connected to the train wire 5 and having the other terminal connected to ground. The circuit of the magnet 7 includes a. condenser 8 for preventing flow of direct current from the train wire 5 to the magnet 7 and also to provide a resonant circuit, responsive only to the cycle frequency of the alternating current generator 2, so that the magnet 7 will only be energized by current from said generator and not by current from the. battery l. Y

In my prior application, Serial No. 170,071, filed February 23, 1927, I have shown and described an electro-magnetically controlled valve mechanism associated with control magnets, and a similar valve mechanism will be employed in connection with the magnets 6 and 7 of the present application. It is not deemed necessary, however, to illustrate and describe said valve mechanism, it being considered sufficient to point out that the magnets 6 and 7 and the valve mechanism in question will be eilective as follows:

When the magnet 6 is energized and the ELECTROPNFUMATIC BRAKE.

Serial No. 210,616.

magnet 7 deenergized, the usual brake cylinder is connected to the atmosphere and t-he brakes are released. lVhen the magnet 6 is deencrgized and the magnet 7 energized, fluid under pressure is supplied to the brake cylinder to effect a service application of the brakes. Then the magnet 6 is energized and the magnet 7 is energized, further flow of fluid to the brake cylinder is cut off, while fiuid in the brake cylinder is retained, in other words, this is a lap or holding position.

lhen both magnets are deenergized an emergency application of the brakes lis effected.

In the drawing, the developed brake switch 9 is shown with the following positions, emergency, service, lap, holding, running, and release.

In the running position, the circuit of' the alternating current- `generator is open, while the circuit of the battery 1 is closed. Direct current is then supplied to the train wire 5 and the magnet 6 is thereby energized. The magnet 7, being responsive only to alternating current ot the cycle frequency generated by the generator 2, is not energized. The magnet 6 being thus energized and the magnet 7 deenergized, the brakes are released.

If the brake switch 9 is turned to service position, the train wire 5 is connected to ground and the circuit of the battery 1 is open, while the circuit of the generator 2 is closed. Alternating current thus flows through the primary coil 3 and thereby current is generated in the secondary coil 4, which current flows through the train wire 5 and energizes the magnet 7, while the magnet 6 remains deenergized, since magnet 6 will not be energized by alternating current.

The magnet 6 being deenergized and the magnet 7 energized, fluid under pressure is supplied to the brake cylinder to effect a service application of the brakes.

The brake valve being moved to service position with the brake switch, a pneumatic service application of the brakes will be eftected on the locomotive.

In lap position, the circuit of the generator 2 is closed and the circuit of the battery 1 is also closed, so' that alternating current is supplied to the train wire and also direct current from the battery l. The magnet 6 is therefore energized by direct current, while the magnet 7 is energized by alternatvaflve lto lap position operates to hold the brakes applied in the locomotive inlthe usual manner.

In emergency position, itlie .oircuitsiof both the generator 2 and the battery l are opened, so that fboth lmagnets 6 and 7 are deenergfized land as a result, itlie brakes :are applied ito effect :an emergency application ot' @the brakes.

In release sposition, as 'in flap, the-circuits o'fboth ithe zgenerator 2 and fthe battery 1 are closed, so Ithatibo'th magnets 6 `and 17 are energized tand the Huid epi-fessure Ain Ithe brake cylinder `iis rretained.

The brake switch :may be operated finde- Ipei'idently lof the brake valve device lby a separate handle and the locomotive mayibe equipped 1With the 'same electrically controlled =brake apparatus as is .applied 'to =the cars.

Having lnow described -my finvention, what -Ilclaim as vnew and desire tosecure 'by Let- 'ters Patent, iszl. In an electro-pneumatically controlled equipment, the combination with -a single 'train `Wire and two mag-'nets connected to vsaid Wire, of means for separately y'controltling said `magnets *through said Wire lincluding an alternating source ot' current anda direct'source of current.

'2. In an -electro-pneumatically `controlled equipment, the combination With `a vsingle 'train Wire and two magnets -connected to said Wire, lof :means for separately lcontrolling .said magnets through said Wire including .means for supplying alternating current and means for vsupplying direct current to said Wire. Y Y

8. In an electrically controlled apparatus, Yt-he'combination with a single train Wire and electrically controlled devices connected to said -Wire, of Aa vsource of direct current, a source of alternating current, and a manufalfly Operable switch vdevice rliaving `positions flonconnecting said source offalternating current to apply alternating current to :said `wirerand the source olf direct current to supply direct current to said Wire'.

4. In an electrically .controlled apparatus, :the combination vWitlrasingle train Wire and electrically controlled -devices connected to said Wire, ot' source ol' direct current, a source Iof Aalternating current, :and a manua'll-y operableswitch device havinga position in which the source of alternating ycurrent is connected to effectthe supplyofalternating current to said wire, a position 'in which the source lof direct current is connected Ito supply direct current to `said `Wire, Landa kposition in which 'both :alternating and direct current is supplied ito said Wire.

5. In an electrically controlled brake, the combination with la single Itrain Wire and magnets connected toisaid Wire for controlling the brakes, one magnet being .energized onlybyalternating current andithe other by direct current,o'f means orsupplying'either direct oralternating'current to said Wire.

In :testimony whereof I have hereunto set -my hand.

THOMAS THOMAS. 

